How to convert decimal numbers to binary in Python: A Step-by-Step Guide

Binary number system is a fundamental concept in computer science, particularly when we deal with low-level operations and digital representation. In this article, I will explore a simple Python code snippet that manually converts a decimal number to its binary equivalent. Understanding the inner workings of this code can provide valuable insights into how binary representation is constructed.

The Code:

def decimal_to_binary(decimal_number):
    ''' This function will convert user defined decimal number to binary '''

    if decimal_number == 0:
        return [0]

    binary_digits = []

    while decimal_number > 0:
        remainder = decimal_number % 2
        binary_digits.insert(0, remainder)  # Insert at the beginning to keep the order
        decimal_number //= 2  # Update the number for the next iteration

    return binary_digits

# Input from user: an integer
decimal_number = int(input("Enter a number to find out its binary digits: "))

# Store the digits in a variable
binary_result = decimal_to_binary(decimal_number)

# Display the result
print(f"The binary representation of {decimal_number} is: {''.join(map(str, binary_result))}")

How It Works:

1. Function Definition:
   • The function decimal_to_binary takes an integer as input and returns a list of binary digits.
   • If the input is 0, it immediately returns a list containing a single digit, 0.
2. Binary Conversion Loop:
   • The code uses a while loop to repeatedly divide the input integer by 2.
   • It keeps track of the remainders at each step, building the binary representation from the least significant bit to the most significant bit.
   • The remainder is inserted at the beginning of the list to maintain the correct order.
3. Displaying the Result:
   • The user is prompted to enter an integer for binary conversion.
   • The code calls the decimal_to_binary function with the user’s input and stores the result in the variable binary_result.
   • The binary digits are then displayed using the print statement.

Test Code / Example:

In simple terms, here is how it works. Let’s say we want to convert number 13 to binary. My function decimal_to_binary will iterate through like this and will give us the binary number:

13 ÷ 2 = 6 remainder 1
6 ÷ 2 = 3 remainder 0
3 ÷ 2 = 1 remainder 1
1 ÷ 2 = 0 remainder 1
Binary: 1101

Understanding binary numbers can massively help to dive deep into low level computer programming. This code snippet is a very simple example of how to convert the number to binary. However, it can be very complex but not impossible to understand binary nitty-gritty. You can simply run the code in your IDE with different inputs, and test the mechanics of the conversion process.

You can visit this link to know more about Binary Number System. I learned a lot from this site. Happy learning 🙂